This invention concerns roof beams, especially for use in constructing conservatories and like structures having roofs comprising panels usually of translucent material supported between roof beams.
Translucent panels for conservatory roofs are generally sandwiched at their edges between upper and lower roof beam forming extrusions or cappings coupled to a glazing bar, usually of aluminum. To provide a good seal above and below the translucent panels, provisions are made for the roof beam to retain gaskets in suitable positions.
Upper roof beam forming extrusions or cappings may have gaskets formed integrally with panel contacting edges thereof and gaskets for the underside of the panels are usually retained in special formations of he aluminium glazing bars. These gaskets have to be fitted to the extrusions on site which takes up time. Also, the extrusions are more expensive to produce because of the additional gasket retaining formations required.
Furthermore, in order to retain the lower beam forming cappings, the aluminium glazing bars require further formations on which the lower beam cappings can locate.
In GB2275958A it was proposed to provide a roof beam construction for use in constructing conservatory roofs comprising a glazing bar and upper and lower cappings therefor having gaskets formed integrally on edges thereof between which a roofing panel is to be retained and means for locating the cappings on said glazing bar, wherein the means for locating the lower capping on the glazing bar comprises the integrally formed gaskets, which in use are trapped between the glazing bar and roofing panel.
The lower cappings are formed with either a flat base or with a base having a pair of angled longitudinal facets. For each type of capping the glazing bar, generally an inverted T in section, has its cross bar correspondingly shaped, ie. either flat or with two angled facets. In forming Victorian style conservatories, both types of glazing bar will usually be used. The glazing bars with the flat base and corresponding cappings are usually used as transom bars extending from opposite sides of a ridge of the conservatory to the eaves and the angled base glazing bars with corresponding cappings are used for forming the Victorian roof end, which is formed with triangular section roofing panels. Thus, in forming a Victorian style conservatory, two different types of glazing bar and lower cappings are required, which adds to the cost. Furthermore, care has to be taken when erecting such a conservatory to ensure that glazing bars are installed in the correct positions.
In GB2315800A we proposed providing a glazing bar for use in forming roof beams of conservatory roofs, the glazing bar being of generally inverted T-section having an, in use, upstanding limb to which an upper capping may be fixed, and a cross bar having a central section and edges, the edge being shaped to extend below the central section to form a recess in the underside of the cross bar. This spacing gave rise to the possibility of the same glazing bar being used for transom and Victorian situations as defined above.
As mentioned above upper cappings for glazing bars have gaskets formed integrally along edges thereof and these are compressed onto and spread outwardly on the roofing panels. The gasket material is usually black and is, of course, visible along edges of the cappings. However, the gasket material can become distorted or discoloured in patched, which detrimentally affects the appearance of the roof.
An object of this invention is to deal with the above-mentioned problem.
According to this invention there is provided a roof beam construction for use in constructing conservatory roofs comprising a glazing bar and on an upper capping therefor having gaskets along edges thereof for sealing a roofing panel to be supported by the glazing bar and means for locating the capping on the glazing bar, wherein the upper capping has its sides stepped inwardly and its gasket material on inwards ends of said stepped sides.
Thus, the gasket material along edges of the upper cappings is spaced inwardly from sides of the cappings and so is substantially hidden beneath the stepped sides when the cappings are in place.
The gasket material may be provided on the cappings in any suitable way. Typically co-extrusion is a suitable technique as is co-bonding.
In a preferred embodiment of the invention the stepped sides of the upper capping form inwards returns that are resiliently flexible, so that the gasket material presses onto the roofing panels to improve contact therewith. The returns may be connected to the sides of the upper capping by lines of weakness allowing them to flex relative to the sides.
In a preferred embodiment of the invention upper cappings have a top and at least one other depending side that is stepped inwardly at its bottom end and has gasket material on a free edge of said stepped bottom end. The upper cappings are preferably extrusions of plastics material, such as polyvinyl chloride and gaskets are preferably of rubber or synthetic elastomeric materials possibly co-extruded with the cappings or bonded thereto. The gasket material is preferably in the form of a strip having two divergent facets that spread outwardly in use. Internally of the capping, formations are provided whereby the capping can be coupled to the glazing bar.
Preferably resilient formations depend from inside of the capping, which formations have outward projections thereon and these formations locate in an upwardly open channel of the glazing bar which has a series of internal recesses or notches for receiving said projections. The provision of a series or recesses or notches for receiving the projections allows the resilient depending formations of the capping to be pressed down into the glazing bar any desired distance depending on the thickness of the roofing panel or panels which is or are being secured in place by the capping and make a snap fit.
The upwardly open channel preferably has converging sides leading to first notches. The converging sides may be planar or curved. The channel is preferably sufficiently deep with sufficient notches or recesses to receive a single size capping irrespective of the depth of the glazing panels being accommodated. A series of two notches or recesses on each side of the channel may be sufficient for most purposes provided the channel is deep enough.
A roof beam according to the invention may be formed for locating the roofing panel on one side thereof, such as when the other side of the beam is to be secured to a wall or may be formed for locating roofing panels on opposite sides thereof for use intermediate ends of the roof structure.
In one preferred embodiment of the invention, the edges of the cross bar may be in the form of troughs extending below the central section of the cross bar. The troughs of the cross bar are preferably formed with outer side walls that also have inwards returns. The side walls are preferably in planes parallel to the plane of the upstanding limb. The inward returns of the side walls preferably have arcuate top surfaces.
The overall height of the cross bar side walls may be chosen to receive transom and Victorian style lower cappings of the same or a similar depth, whilst the recess on the underside of the cross bar can accommodate the angled facets of the Victorian lower capping base. The glazing bars of the invention may also accommodate glazing panels at a variety of angles. Furthermore, as the same glazing bars may be used for transom situations and for roof end situations where glazing panels are angled relative to each other, it may be possible to use the same size top cappings on both rather than having to use a larger size top capping on the roof end glazing bars.
Where the cross bar recess is formed by continuations of side walls below the cross bar, these continuations may be shaped so as to provide means of engagement with cooperating formations of a lower capping for the glazing bar. Such engagements may comprise, for example, corresponding hook like formations or may comprise ribs that snap fit into channels. Such channels are preferably formed internally of the lower cappings.
Thus, with this type of formation for the cross bar, a capping having either a flat base or an angled facet base can be accommodated thereon, so that the need for two different formations of glazing bar can be eliminated. By having the top surfaces of the inward returned of the side walls arcuate or curved, integral gaskets on top edges of the capping can be accommodated irrespective of the angle of the co-extruded gasket.
The inward returns of the side walls preferably also have top surfaces that are profiled or roughened in order to provide improved grip for the capping on the underside of the cross bar especially for co-extruded gaskets on edges of cappings, which in use are sandwiched between the glazing bar and glazing panels.
Conveniently the troughs at each side of the glazing bar cross bar provide draining channels for collecting and directing water which has penetrated the roof beam. So that it can run off via the roof eaves. To improve drainage further, it is preferred that the central section of the glazing bar cross bar be inclined downwards from each side of its junction with the upstanding limb, so that any water collected in the glazing bar can run into the troughs. As any fixings made between the glazing bar and other conservatory components at the ridge or eaves will generally be made in the central section, such as by way of screws or bolts, it is advantageous to have the extra drainage facility, so that water cannot collect around such fixings and cause corrosion.
For some situations, especially in large conservatory constructions, where glazing bars will be unsupported over a considerable length, there is a risk of them twisting. Thus, a preferred glazing bar for the beam construction of the invention is of generally inverted T-section and has its upstanding limb in the form of a hollow section duct.
The upstanding limb of the glazing bar may be of any suitable cross section. One suitable cross section is a rectangular cross section but a tapered section either upwardly or downwardly, such as of a triangular cross section, may also be very suitable for the invention, especially in the form of an isosceles triangle either way up. A triangular section duct is believed to be advantageous in providing a self resolving shape for lateral forces.
Another type of glazing bar for use in this invention has two or more ducts, preferably spaced apart by single web stems. Preferably such ducts are of rectangular, especially square, section.
Generally the double web duct should be as small as possible without losing the advantage of strength. That is to facilitate extrusion of that type of glazing bar, say from aluminium or aluminium alloy, it being easier to extrude smaller rather than larger enclosed sections. A preferred shape for the duct has a flat top and convergent sides from the flat top to a curved base.
The ducts of preferred glazing bars for this invention, as well as giving torsional stability to the glazing bars, may also be used to carry service cabling or piping and to provide locations for connecting members, such as fixing cleats or brackets of a tennon type. Furthermore, hollow duct glazing bar have improved xe2x80x9cUxe2x80x9d values compared to single stem glazing bars.
Glazing bars for the invention may be secured to other components of a roof system by means of screws, bolts or the like through the cross bars thereof. However, for some situations end fixing of glazing bars may be desirable. For that purpose the upstanding limb of a glazing bar may be formed with a screw or bolt port to receive same in a longitudinal direction of the glazing bar. As the glazing bars used in the invention will normally be formed as extrusions, the port will run the length of a glazing bar section and be available, therefore, at opposite ends of the glazing bar to receive a screw, bolt or other suitable fixing.
For glazing bars having a single web upstanding limb, the screw port will conveniently be situated just above its junction with the cross bar or at the intersection of the upstanding limb and cross bar.
For glazing bars having their upstanding limb in the form of a hollow duct i.e. having two upstanding webs, the screw port may be formed as part of a the duct preferably either at or just above the base thereof. Alternatively, the screw port may be formed in a single web upstand between the cross bar and a double web duct.
The invention further provides a roof beam comprising a glazing bar of either aspect of the invention with upper and lower cappings fitted thereto.
A preferred lower capping is of extruded plastics material, such as PVC, and is preferably formed as a channel section with either a flat base or with a base having a pair of angled longitudinal facets the gasket material is preferably co-extruded or bonded onto the capping and is preferably of rubber or synthetic elastomeric material. The gaskets preferably extend inwards from opposite sides of the channel and may have deformable resilient ribs or the like, especially at edges and also possible centrally thereof to provide a good seal when compressed. Preferred gaskets are generally arcuate in section, so that they are concave on their underside. This feature may be of advantage in fitting the cappings to glazing bars by allowing more room for the gaskets to be slipped over edges of the glazing bar cross bar. Internally of the lower cappings are preferably one or more spaced projections or ribs to ensure correct alignment of the glazing bar and capping when fitted together.
The lower cappings may have their bases formed with a relatively flexible mid-section, which nay facilitate fitting thereof to glazing bars. In one preferred form the lower capping base is formed with a co-extruded rubber or elastomeric strip centrally thereof along its length.